title: Effect of hypoxia on the superficially exposed carbohydrates of subcellular fractions of guinea pig cerebral cortex.
abstract: Experimental hypoxia led to changes in carbohydrate-containing macromolecules located on the microsomal and synaptosomal membrane surface. It was found that hypoxia reduced the external membrane-bound sialic acid content in microsomal and synaptosomal fractions. On the other hand, a decrease in fucose content of proteins in hypoxic synaptosomal fraction was found. Similarly, a decrease was observed in the amount of 3H-labeled concanavalin A bound to the microsomal and synaptosomal glycoprotein fractions. Treatment of microsomal and synaptosomal fractions with galactose oxidase followed by reduction with tritiated potassium borohydride resulted in a significantly higher incorporation rate of tritium into the hypoxic membranes. This was accompanied by an increase in the endogenous glycoprotein galactose transferase activity both in microsomal and synaptosomal fractions.
mesh_terms: D000818:Animals; D050260:Carbohydrate Metabolism; D002540:Cerebral Cortex / Q000378:metabolism*; D005643:Fucose / Q000378:metabolism; D005700:Galactosyltransferases / Q000378:metabolism; D006017:Glycolipids / Q000096:biosynthesis; D006023:Glycoproteins / Q000096:biosynthesis; D006168:Guinea Pigs; D006601:Hexoses / Q000378:metabolism; D000860:Hypoxia / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism*; D008565:Membrane Proteins / Q000096:biosynthesis; D008861:Microsomes / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D011952:Receptors, Concanavalin A / Q000378:metabolism; D012794:Sialic Acids / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D006017:Glycolipids; D006023:Glycoproteins; D006601:Hexoses; D008565:Membrane Proteins; D011952:Receptors, Concanavalin A; D012794:Sialic Acids; D005643:Fucose; D005700:Galactosyltransferases